Refrigerating apparatus



Filed Sept. 9, 1932 2 Sheets-Sheet 1 R. my M cv ik #v w Tief as" .Mm 2 u.. P Y n MW-e -2 B m2 www www m ro.

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ATTORNEY.

oct. 22, 1935'. R. w, DOES 2,018,515

REFRIGERATING APPARATUS Filed Sept. 9. 1932 2 Sheets-Sheet 2 ;"IFM A65 26 u I Z7 INVEN l OR.

ATTORNEY Patented Oct. 22, 1935 PATENT oFFlcE 2,018,515. IEFBIGEBATING APPARATUS )muah w. non, Detroit, Mich.

nlig'nor to Kelvinatos Corporation, Detroit, Mich., a corporation olMlclllm museum september s, mz, serai No. 632,341 somma (or zen-141) This invention relates to refrigerting pvratus and more particularly to fluid compressors for use with such apparatus.

One of the objects of the invention is to prol vide a newy and highly efiicient fluid compressor for'refrlgerating apparatus.

Another object of the invention is to provide a durable and simplied type of iiuid compressor having a minimum number of working parts which are economical to manufacture and which are easily assembled.

Another object of the invention is to provide a fluid compressor driven by an electric motor and to arrange for operably connecting the compressor to the motor and in a manner whereby the motor is permitted to gain momentum before assuming the working load of the compressor to prevent the possible destruction of the motor due to large starting load.

Further objects and advantages of the present invention will be apparent' from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present ,invention is clearly shown.v

In the drawings: v

Fig. 1 is a 'diagrammatic representation of Ac. refrigerating apparatus embodying features of :rw-invention;

Fig. 2 is a side view in cross section of a motor-compressor unit embodying features of my invention: l 2 Fig. 3 is a view takenalong line 3-6 of Fis.

; and I Fig. 4 is a view taken arrows 4-4 of Fig. 2.

Referring to the drawings, and particularly to Fig. l, the numeral 26 designates in general a refrigerating system diagrammatically represented as including a refrigerant condensingv element 2l and a .refrigerant evaporator 23. The evaporator 23 as shown in this instance, is of the flooded type, although other types may be used. The condensing element 2| comprises in general a^ condenser 26, ahigh side float mechanism 26, and a duid compressori. 21 which compressoris to be hereafter more fully described. g Liquid refrigerant-is supplied to the evaporator from the neat mechanism zc through a uquid Isupply conduit 26, and evaporated refrigerant is ,withdrawn fromthe evaporator through a vapor conduit 26 by meansoffthe-compressor 21. The compressor 21 compresses the refrigerant vapor and delivers it to the condenser 26 wherein it is liquefied and from which it is delivered to the oat 26 and the cycle repeated.

inthe direction of the Referring more in detail to the drawings, and particularly-to Figs. 2, 3 and 4, the compressor 21, as shown, is preferably enclosed in a hermetically sealed casing 32. 'I'he casing 32 is preferably constructed of a sleeve formed such 5 as by casting, and closure members 36 and 38. for closing the ends of the sleeve 35. The closure members 36 and 36 are formed to be press-fitted .within the ends of the sleeve to form a fluid tight casing. The closures are .also secured to the l0 sleeve, preferably by welding.

Another casting 43 is tightly press-fitted within the sleeve 36 and includes a vertically extend-` ing wall 45 disposed between the end closure members I6 and 36, thusdlviding the interior of l5 the casing into two separate compartments 46 and 46. The vertically extending wall '45 is formed with a boss 46 within which is provided a bearing 66, preferably integral therewith. A shaft 5l is journaled to rotate within the 20 bearing 60. The fluid compressor 21 is disposed within the compartment 46 and is operated by the rotation of shaft 6|. Shaft 5I is in l turn driven by means of an electric motor, which `is also preferably enclosed within the casing 32 25 and within the compartment 46 thereof. The electric motor comprises in general a rotor 52 and a stator 5I. The rotor 62 is provided with a bearing 54 and is mounted to rotate freely on the shaft 5i. A collar 65 is provided to act as a 30 thrust bearing for maintaining the rotor in position and is fastened to the shaft by'means of a set screw I6. 'Ihe stator 53, as shown, may be secured and held in position by the casting 43. y

In motor-compressor units, in which anelec- 35 tricj motor having a relatively low starting torque is employed for operating the compressor, some means must be provided for permitting the motor to come up tc? a certain speed before assuming the working load. I propose to employ a relal tively small split phase electric motor for driving the compressor 21, by means of a yieldable or resilient driving connection which permits the rotor to gain momentum before assuming the load of the compressor, thus preventing the possibility of destruction to the motor.

The yieidable connection comprises va resilient coiled member 66, preferably made of spring steel, having one end suitably secured to the shaft 5i, such as by a pin 41, and the other end 50 secured to a pin 51, which pin is secured to the rotor 62 adjacent /the periphery thereof. Thus Vit will .be seen that the force of the rotor is \not applied to rotate the shaft ill until the coiled spring steel member |56 is wound around the shaft 5|, thus locking it to the rotor, during which time, the rotor having made several revolutions, the magnitude of the torque tending to produce -rotary motion of the shaft is increased suffi- \ciently to overcome the opposing torque of the compressor. driving connection, an electric motor havingthe above characteristics may be employed to drive a refrigerant compressor.

'Ihe compressor 21 is of the so-called rotary type and includes a cylinder block 59 clamped between the vertically extending wall 45 and an outer plate member 88 by means of screws 8|. Within the cylinder block 59 there is provided a chamber 63 for refrigerant to be compressed and within the chamber 53 there is disposed a piston lill. The piston 84 is arranged for movement about the cylindrical wall 'of the chamber 63 by means of an eccentric 85 carried by the drive shaft 5|. 'I'he shaft 5| extends through the'oompression chamber 83 and is journaled inal bearing 61 carried by the plate `60.

As shown in Fig. 3, I have disposed the refrigerant inlet port 11 and the outlet port 18 in close proximity to obtain eiiicient compression of the refrigerant. In order to prevent therefrigerant, entering the inlet port 11, from passing to the outlet port 18 before being compressed, and to also provide a durable compressor having a minimum number of. working parts, I provide the piston 84 with a projecting portion or blade 88 which is arranged to project into the outlet port 18, thus dividing'lthe compression chamber 83 into an inlet side 82 and an outlet side 83. 'I'he blade `80 may be suitably secured to the piston, as shown, by counter-sunk screws 84. 'I'he wall defining the outlet port 18, sion chamber 83-and the inlet port y11, consti- Itutes a bearing surface 85 over which the blade 80 slides or reciprocates in a rocking motion during the Itravel of the piston about the compression chamber.V N

In Fig. 3 it will be seen that the center of rotation of the eccentric is only a small distancel from the center of rotation of the shaft 5| so that the rocking motion of the blade 88 is correspondingly'small. The width of the opening or outlet port 18 is made suivllcient to allow for the rocking ofthe blade plus a small passage 88 for exhausting the compressed refrigerant between the blade 80 and the right sideof the port 18, as viewed in Fig. 3, which .opening is always vin open communication `with the compression chamber 83. The compressor is designed so that the piston 64 moves in a clockwise direction as viewed in Fig. 3 and as the piston travels about the compression chamber 831i: opens and closes the inlet port 11.

To insure that none 4of the refrigerant entering Y the inlet portV 11 may escape between the bearing surface and the blade 88, I have provided fork resiliently maintaining the blade 88 in contact with the bearing surface 85 by means of a' spring 81. An opening 89 is drilled through to the out- Ilet port 18 and substantially at right angles thereto, and the spring 81 is arranged in the opening 89 to urge a contact member 98 against the blade .80,'which in turn is urged against the bearing surface 85. -The tension made adjustable by means of an adjusting screw 92. Preferably, the adjusting screw 92 is provided withn an axially extending bore 93, the purpose of which is to allow lubricating oil contained in compartment 46, the level of which I have in- Consequently, by means of this adjacent the compresf orator.

of the spring 81 is also dicated at 94, to pass in and out of the opening 89. Without this arrangement there is the possibility of oil leaking into the opening 88 and causing a hydraulic lock therein.

In order to avoid passing the compressed re- 5 frigerant through the oil contained in compartment 48, I provide a closed chamber |08 in communication with the outlet port 18 and arranged to deliver the refrigerant from chamber |08 to compartment 48 wherein little or no oil is contained. Preferably, the lower exterior p ortion of the cylinder block 59 is formed with a flat surface 95 and a casting member |8| is secured thereto by screws |83iand formed to cooperate with the fiat surface 95 `to `-provide the chamber |88. 15 Within the chamber |88 there is provided a reed valve |85 for controlling, the refrigerant passing from the outlet port th'ereinto and forprevent ing back pressure in lthe compression chamber- 63 of the hher compressed refrigerant in cham- 20 ber |88. e reed valve |05, as shown, may b secured by one end to the flat surface 95 of the cylinder block by screws 91. A passageway |81 in communication with the chamber |80 is provided in the cylinder block, and horizontally disposed 25 passageway |89 in communication with passageway |01 (see Fig. 2) is provided in the vertical extending wall 45 of the `casting 43 in communication with compartment 48. Thus, after the gaseous refrigerant is compressed it passes through the outlet port 18 to the chamber |88 and from the chamber through passageway |89 to the compartment 48, after which it passes through Ithe outlet fitting ||8 and is under pressure to the condenser 25.

Preferably, the outlet fitting is located in the compartment 48. In order to deliver the high pressure gas from the .compartment 48 to compartment 46 so that it may enter the fitting 8, I

have provided a passage |28 in the vertical wall o 45. By this arrangement the compressed gas in compartment 48 enters the inlet end |22 of passage |20 and is discharged into compartment 48 at the outlet end |24' of passage |28. Also, by this arrangement, any oil which may be delivered to the compartment 48 is returned to compartment 48 through passage 28, the highest level to which oil in compartment 48 could rise, being the inlet end |22 of passage |28. This oil is returnedV by the pressure of refrigerant in compartment 48 on the oil thereinl Preferably, the system is intermittently operated in response to changes in pressures within conduit 28. The evaporator 28 is of the Aflooded type in which the pressure of the refrigerant bears a direct relation to the temperature of the evap- Consequently, the operation of the system will be controlled in response to changes in temperaturewithin the evaporator 2l. In order to control the operation fof the motor-compressor unit in response to changes in pressure within the conduit 28, I have provided an automaticswitch t H2, which is adapted to connect and disconnect the motor to and from the power mains ||4 at 65 connected by a novel driving connection which 79 permits the motor to operate for a period of time before the load of the compressor is assumed. This arrangement is particularly advantageous in that an inexpensive motor maybe utilized to drive a refrigerant compressor without danger of the 75- delivered as aoiasis piston mounted for operation in said compression cylinder, a blade rigidly /attached to the piston to provide a partition between the high and low pressure sides of the cylinder, said blade extending into and being of lesser width than said recess and operating with a sliding and rocking contact with said stationary protruding bearing surface, said cylinder block also being provided with an outlet passage for discharge of high pressure fluid, and means tor maintaining engagement between said blade and bearing surface to.

seal said high and low pressure sides of said compression c'ylinder' and to maintain a clearance spaceinsaldrecessonthesideoppositesaidbearing surface to permit said high pressure iiuid to pass to said outlet passage, cludlng a push rod positioned au right angle to said-blade and alidahlein said' cylinder wall and a compression spring carried by said cylinder wall and tending to urge said push rod against said blade.

2. Pumping mechanism comprising a cylinder block provided with a compression cylinder and a recess adjacent said compression cylinder, a protruding bearing surface extending inwardly into said recess, a piston mounted for operation in saidcompression cylinder, a blade rigidly attached to the piston to provide a and low pressure sides of the a sliding contact with said surface. said cylinder block with an outlet passage for discharge of high pressure iiuid adjacent said bearing, and means for maintaining engagement between said blade and bearing surface to seal said high and low presprotruding bearing sure sides o! said compression cylinder 'and to` -maintain a clearance space in saidvrecess on the.

side opposite said said means ininder wail and a compression spring carried by saldcyundernnanandinstourgesaidpush rodminatsaidblade.

RALPH w. noso.

partition be- 1o also being provided 1s 

